Rosie O'Donnell tells the emotional and tragic story of her Irish ancestory - SEE VIDEOS

Actress, TV and radio host Rosie O'Donnell had a chance to uncover the history of her Irish ancestors on NBC's show "Who Do You Think You Are.” The result was a tragic and cathartic story that uncovered the hardship that her mother's family had suffered in workhouses in Ireland before fleeing for Canada. The show also gave O’Donnell a closer connection her mother.

O'Donnell's mother died of cancer when she was just 10 years old. Her death has left a void in O'Donnell’s life. Learning of her family's story of suffering in Ireland, O'Donnell was emotional but also grateful.

She said, "It doesn't diminish my own suffering, but it's not any longer the focal point of my existence. I think that's a gift."

O’Donnell’s grandfather and his family had lived in poverty and dire hardship, relying on workhouses, before they eventually fled by ship to Canada.

She feels her new found family history put her life into perspective. She said, "I had a mother who died. That's all I knew. And that felt like an unlivable tragedy; like an unbearable tragedy. But now, I think to myself, her life existed because of the suffering and pain [of her ancestors]."

O’Donnell believes that the struggle her ancestors and her mother endured is what made it possible for her to live the life of success and privilege she has enjoyed.

O'Donnell had been unaware of this part of her Irish history before working with the show. She said, "This huge part of Irish history [is] almost non-existent…I think that needs to be fixed; needs to be told."

She also discovered that her great grandfather's first wife had died due to a kerosene oil lamp explosion. O'Donnell was aware of the photograph of a woman that had always been hung in the family home, but she never knew the story behind it.

This woman was her great grandfather's first wife Anna Murtagh. Her great grandfather's beloved had suffered for 20 days before she passed away in December 1881.

On the show O’Donnell said she was shocked and upset by the news. "That's a long time to suffer. I'm really upset to hear that my great-grandfather's first wife, Anna, died so tragically. I've got to find out more."

Having tracked down a newspaper clipping at the Brooklyn Historical Society, O'Donnell discovered that the woman was preparing breakfast for her grandfather when the infant pulled the lamp over the stove and set Anna alight. The clipping said that Anna had lingered in "great agony" before dying.

O'Donnell commented, "How heroic. She knew she was on fire; she probably did what every mother would do -- save the child first. What happened to that infant?"

This child was called Elizabeth and she was O'Donnell's grandfather's half-sister. This led O'Donnell to find Elizabeth's 10 grandchildren. She had lunch with them in New Jersey.

During the show O'Donnell visited Brooklyn, New Jersey and Canada, and her family's story eventually led her to Co. Kildare in Ireland. O'Donnell also visited the workhouse, the location where her relatives had lived before setting out across the Atlantic Ocean.